I am trying to get a little more into modding by creating my own stuff.
So I decided to start slowly by creating my own nameplate. I used the "Automatic Nameplate Generator v1.1" to do so.
When i create the .dds file, everything is (I think) fine. I got a Pink and Blue image with the name I want, and I export it as a BC5 / ATI2 (3dc) with no mipmap file.
Then, I open Smash Forge, open my original chrn_11 file (here it's KoopaJr_01), and I got a black screen as a preview. That's when something seems wrong.
Still on Smash Forge, I right click on my ID file, select "Replace" and I replace my chrn_11_KoopaJr_01 file with my previous .dds file. When I do this, the black screen preview is still black but with red blurred lines on it. I noticed the format file changed to CompressedRgRgtc2 with the vanilla file to RedRgtc1 with the replaced file.
When I put the file on my game, the file loads (no freeze), but the name is just a glitchy unreadable thing.